ANAT 321 Lecture Notes - Lecture 17: Olfactory Receptor Neuron, Olfactory Bulb, Olfactory Receptor
30 Aug 2016
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Document Summary
Visual system & somatosensory have organized maps, important to know location. Paramecium hit low ph go crazy; don"t have nervous systems; chemosensation. Dog may have olfactory map in the way we have visual map. Human olfactory bulb very small relative to brain. Mouse olfactory bulb enormous relative to brain olfactory system very prominent. Receptor cells are bipolar neurons: dendrites sticking out into nasal mucosa of nasal cavity, axons project up through cribriform plate (cranial nerve i) into olfactory bulb. Odour molecules dissolve in mucous layer accessible to receptor endings. Stick electrode in cilia, membrane depolarizes in response to particular odorant. Neurons don"t grow after development; one exception is olfactory receptor neuron. Graded depolarization, #ap function of size of receptor potential. G-protein coupled receptors: when activated activate g-proteins activate 2nd messengers in cell. In rat: 1000 diff receptor proteins, each receptor protein responds to specific molecular structure. Human: few hundred types receptors can detect thousands of odours.
